POS0835 RELAPSE RATES IN NEWLY DIAGNOSED AND ESTABLISHED PATIENTS WITH ANTI-NEUTROPHIL CYTOPLASMIC AUTOANTIBODY (ANCA)-ASSOCIATED VASCULITIS
Authors: K. Fitch, C. Bazell, S. Metz, I. Von Hennigs
Journal: Annals of the Rheumatic Diseases (2022)

Background Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis is a life- or organ-threatening condition in which patients experience severe inflammation of small- to medium-sized blood vessels. Clinical relapses are common in ANCA-associated vasculitis and previously reported rates vary between 21-89% at 5 years depending on the regimens used for induction and maintenance (1). Relapses require repeated treatment with immunosuppressive therapy and increase the risks of adverse events. Objectives Identify the incidence of relapse in newly diagnosed and established granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) patients in commercially insured and Medicare fee-for-service (FFS) populations. Methods Using the 2016-2019 Milliman proprietary commercial claims data and Medicare 100% FFS Innovator Research data, newly diagnosed and established GPA and MPA patients were identified in index years 2017 and 2018. Newly diagnosed patients were identified as those with at least two qualifying claims on different dates of service, coded with a GPA or MPA ICD-10-CM code, and no claim coded with GPA or MPA in the 12 months prior to their first claim. Established patients required 12-months continuous enrollment in the year of their established status and 12-months continuous enrollment in the year prior to their established status. Relapses for incident patients were identified during the 7 to 12 months after the index date for newly diagnosed patients to avoid mischaracterizing claims around the time of the initial diagnosis as relapses and over a 12-month period for the established patients. Relapse was defined based on specific inpatient and outpatient claims with a GPA or MPA diagnosis code or claims coded with one major or at least three minor vasculitis signs or symptoms followed by a claim within 30 days for plasmapheresis or cyclophosphamide or glucocorticoids (&gt; 20 mg prednisolone equivalent) or 2+ rituximab claims within 30 days of each other. Relapse had to occur 30 days after the previous event and 6 months after index date for incident patients. Results 542 (GPA) and 83 (MPA) commercially insured newly diagnosed patients with 12 months eligibility following their index date and 1,748 (GPA) and 184 (MPA) commercially insured established patients were identified. 15.5% (GPA) and 15.7% (MPA) newly diagnosed patients relapsed during months 7-12 after diagnosis and 27.9% (GPA) and 29.3% (MPA) established patients relapsed over a 12-month period. 2,397 (GPA) and 655 (MPA) Medicare FFS newly diagnosed patients with 12 months of eligibility following their index date and 5,955 (GPA) and 833 (MPA) Medicare FFS established patients were identified. 19.3% (GPA) and 27.2% (MPA) newly diagnosed patients relapsed during months 7-12 after diagnosis and 33.5% (GPA) and 40.2% (MPA) established patients relapsed over a 12-month period. Conclusion Using administrative healthcare claims, we observed relapse rates after GPA and MPA diagnosis ranging between 15.5-27.2% in months 7-12 after diagnosis for newly diagnosed patients and between 27.9-40.2% over a 12-month period for established patients. There is an unmet need for new therapies that sustain remission and decrease relapse rates in patients with ANCA-associated vasculitis. This is an important clinical strategy to reduce the risks of adverse events from long-term immunosuppression therapy and decrease end-organ damage. References [1]Salama AD. Relapse in Anti-Neutrophil Cytoplasm Antibody (ANCA)-Associated Vasculitis. Kidney Int Rep. 2019;5(1):7-12. Disclosure of Interests Kate Fitch Consultant of: ChemoCentryx, Carol Bazell Consultant of: ChemoCentryx, Steven Metz Consultant of: ChemoCentryx, Irene von Hennigs Shareholder of: ChemoCentryx, Consultant of: ChemoCentryx, Employee of: ChemoCentryx